Relay structure with improved armature pivot



1965 L. J. GRESHEL ETAL 3,198,909

RELAY STRUCTURE WITH IMPROVED ARMATURE PIVOT 3 Sheets-Sheet 1 Filed March 24, 1960 lllllllmfi S I, H m m m W 5W 5M mm a z MGM w RELAY STRUCTURE WITH IMPROVED ARMATURE PIVOT Filed March 24, 1960 Aug. 3, 1965 L. J. GRESHEL ETAL 3 Sheets-Sheet 2 JNVENTORS Leonard J Greshe/ BY Gem/d E Bos/er United States Patent 3,198,90? RELAY STRUQTURE WITH IMPROVED ARBr IATURE PIVOT Leonard J. Greshel, Cohasset, Mass, and Gerald E.

liliosler, Galion, Ulric, assignors to North Electric Comparry, Galion, Shin, a corporation of Ohio Filed Mar. 24, 1960, Ser. No. 17,431 19 Claims. (Cl. 200-104) The present invention relates generally to an improved relay construction, and the present disclosure is a continuation-in-part of the application which was filed by Greshel and Bosler on March 16, 1959, and which received Serial No. 799,589, now abandoned, and which is assigned to the assignee of this application.

The object of the present invention is to provide an improved construction for relays, which construction facilitates manufacture of relays to exacting specifications by mass production methods, accommodates decrease in the size of relays of a given capacity, mitigates improper operation of the relay when subjected to rectilinear and/ or curvilinear acceleration or deceleration-even translational accelerative forces in the order of 50 gravities in any direction, renders the relay capable of Withstanding vibrations of from to 3,000 cycles per second without mechanical damage and without adversely affecting operating characteristics, permits vibration of the relay at resonance for prolonged periods without affecting operating characteristics, accommodates operation of the relay over a temperature range of from 65 degrees C. to +125 degrees C., renders the contacts of the relay essentially bounce free, maintains accurately controlled pull-in and dropout values irrespective of the conditions to which the relay is subjected, facilitates hermetic sealing of the relay, and otherwise satisfies existing specifications applying to relays.

In more specific terms, it is one object of the invention to provide a relay construction including means defining an improved magnetic circuit resulting in greater uniformity in magnetic power and higher magnetic forces than heretofore obtained, whereby mass production of the relay is facilitated.

Another object of the invention is to provide a relay construction including an improved pivot mounting for the relay armature which eliminates spurious movements at high pulsing rates and under shock and vibration, said mounting including a pair of pivot balls welded to the armature and journallcd respectively in cylindrical sockets, one of which sockets is preferably provided in an adjustable screw.

A further object of the invention is the provision of an improved assembly for relays affording marked structural stability; the assembly including a pair of spaced parallel coil cores defining pole pieces at their upper ends, a bottom strap to which the two cores are fixedly secured, a yoke fixed to and physically connecting the two cores adjacent the upper ends thereof and including depending portions fixed to said bottom strap, said depending portions defining mounting means for contact assemblies or pile-ups, and an armature mounting bracket fixedly secured to one of said pole pieces above said yoke, whereby the components of the relay are all united in an in tegrated structure.

A still further object of the invention is the provision of an improved relay construction including accurately settable screw threaded adjustments for all mechanical components affecting relay operation, namely, each stationary contact, the armature pivot, the residual means and the return spring, thereby to facilitate attainment of maximum sensitivity and uniformity.

Yet another object of the invention is to embody in the improved relay construction above defined an imice proved contact structure including a separate leaf spring for mounting each movable contact thereby to facilitate diverse circuit arrangements, each of said springs closing its contact with the respective stationary contact by its own spring force for resisting vibration and mitigating contact bounce.

A further object of the present invention is to provide a relay structure which incorporates a new and novel contact-actuating arrangement, and particularly a novel contact actuating arrangement which permits the provision of a plurality of different contact functions as by the same structure in different states of adjustment.

Other objects and advantages of the invention will become apparent in the following detailed description.

Now, in order to acquaint those skilled in the art with the manner of making and using our improved relay, we shall describe, in connection with the accompanying drawings, a preferred embodiment of the relay structure and the preferred manner of making the same.

In the drawings:

*IGURE 1 is a side elevational of the preferred embodiment of the relay construction of our invention, the can within which the relay normally would be hermetically sealed having been removed to reveal the constructional details of the relay per se;

FIGURE 2 is a plan view of the relay;

FIGURE 3 is a perspective view of our improved structural assembly for relays;

FIGURE 4 is a fragmentary vertical section taken substantially on line 4 i of FIGURE 2 and revealing our improved armature pivot construction;

FIGURE 5 is a fragmentary vertical section of the coil cores and bottom strap employed in our improved relay construction; and

FIGURES 6A-6D are schematic representations of certain members of the relay structure, and the novel man nor in which the various adjustments of certain of said members effect a plurality of different switching functions.

Referring now to the drawings, and particularly to FIGURES 1 and 2, we have shown a preferred embodiment of the completed relay of the invention. This relay is of the same type as that disclosed in the patent to Hall et al., 2,767,280, the relay including a balanced armature 10 pivotally movable about a central vertical axis that is disposed centrally between and parallel to the axes of the coil cores 12 and 14 so that application of magnetic forces to the armature from the fiat pole faces 16 of the coil cores will be exerted at equal distances from the armatures axis. The armature in turn carries a contact actuator 18 that is balanced relative to and centered on the pivot axis of the armature. The actuator includes a pair of lever arms 20 of equal length, and preferably each of a length equal approximately to the length of one arm of the armature, extending outwardly from the armature for engagement with the movable members of respective contact assemblies or pile-ups 22 that are mounted equal distances to opposite sides of the common plane of the coil core and armature axes. The contact assemblies are so mounted that the central vertical axes thereof define a vertical plane that is perpendicular to and intersects the plane of the core axes centrally between the axes of each pair of axes, and the pivot axis of the armature is coincident with the line of intersection of the two planes thereby to provide a completely balanced assembly.

A prime improvement afforded by this invention in relays of the described character is an improved structural assembly which is illustrated in FIGURE 3. In this assembly, each of the coil cores f2 and 14 is provided with an integral enlarged pole piece 24 at its upper end and an integral radial flange 26 adjacent but spaced from its lower end. Adjacent their upper ends, the cores 12 and 14 are rigidly interconnected by means of a non-permeable yoke 28 which includes upper strap portion 30 extending etween the cores and a pair of leg portions 32 on each side of the relay depending downwardly from the sides of the strap portion so as to be disposed equal di tances to opposite sides of the plane of the axes of the coil cores. The u; per strap portion 3% is provided with a pair of openings therethrough of the same configuration as the pole pieces so that this strap portion will serve not only to interconnect the cores in spaced parallel relation but to locate the flattened faces it; of the pole pieces 24 for exact correlation with the armature it). The strap portion is located substantially at the juncture between the core portion proper and the pole piece, and the strap is fixedly staked to the pole pieces by means of integral tabs 3 thereby rigidly to interconnect the upper end portions of the cores.

At its lower end, each of the cores 12 and 14 includes a cylindrical extension 36 that is rigidly secured to a permeable lower or bottom strap 38 which physically and magnetically connects the lower ends of the permeable cores l2 and 14. Preferably, the extensions are inserted through spaced holes in the strap 33 until the flanges 26 thereof Contact the strap, and the lower ends of the cores are then peened over fixedly to secure the cores to the strap with the flanges 26 in intimate engagement with the strap, and with the lower strap 38 extending in spaced parallel relation to the upper strap 33. in like manner, the depending leg portions of the yoke 28 are fixedly staked to the lower strap 3:: thereby fixedly to unite in an integrated assembly the two cores, the two straps and the two legs, Preferably, to insure exact assembly of the described components, the depending portions 32 include reduced extensions which are staked into locating slots in the lower strap 33.

As part of the integrated structural assembly, the armature it} is mounted to the above described assemblage by means of a bracket 42 that is welded to one of the pole pieces in fixed relation thereto. Preferably, one of the pole pieces 24 is provided with a fiat side face id to which the bracket is welded thereby to insure exact location of the bracket, and consequently, exact location of the armature.

The specific manner of mounting the armature is a further improvement afforded by the present invention, and this improvement is depicted in detail in FIGURE 4. R ferring however first to FTGURE 3, the bracket 42 itself is of generally U-shape and includes a bight portion and a pair of legs and the bracket being mounted on its side with the bight portion 46 thereof secured to one pole piece and the legs thereof extending horizontally into the space between the pole pieces. The bight portion of the bracket is preferably of a height less than the height of the pole pieces, so that the same will not project above the tops of the poles. The lower leg 48 of the bracket is provided with a socket 43a therein which, in the completed assembly, is aligned axially with the line of intersection of the planes of the core axes and the vertical axes of tie contact assemblies. This socket 48a is formed by an accurately machined hole in the leg 58 and an end plate 52 press-ntted into the lower end of the hole. The upper leg Ell of the bracket is provided with a tapped bore therethrough in exact vertical alignment with the socket 43a in the lower leg, and a precisely machined screw 54 having a fine micrometer thread is threaded into the bore. in its lower surface, the screw is provided with an accurately formed cylindrical socket 5 3a which is aligned vertically with the socket 48a in the lower leg 48.

The armature it), together with the contact actuator llil, is adapted to be pivotaliy mounted on the bracket 46 by means of an improved pivot construction, now to be described. ln assembly, the actuator is fixedly secured, as by welding, to the upper surface of the armature lit The actuator is located centrally on the pivot axis of the armature and the lever arms 2-13 thereof pro ect outwardly in opposite directions from the armature. Since the armature must be located at an inclination to the plane of the core axes, the actuator is suitably disposed in incli ed relation to the armature, at an angle complemental to the angle of inclination of the armature, for extension toward the contact assemblies 22.

In the lower surface of the armature and in the upper surface of the actuator, We provide small conical locating recesses which are aligned precisely with the central vertical pivot axis of the armature. Located in each recess, and welded to the armature and the actuator thcreat, is a ball 55 which projects outwardly from the armature to form the pivot pin thereof. Each ball is received in intimately journaled relation in the respective cylindrical socket in the leg 43 and screw 54, and has circular line contact with the surrounding cylindrical wall of the socket irrespective of its location longitudinally of the socket, whereby the balls, the armature and the actuator are firmly and positively retained against side play. After the balls are positioned in the sockets, the screws 54 is adjustable to locate the balls properly in their sockets.

in relay constructions of the character herein described, a certain degree of end play of the armature pivot can be tolerated, but side play or slop is not permissible since it would result in unbalance of the armature. With prior armature mountings, extreme care was required in assembly since screw threaded adjustment of one hearing would affect both end play and side slop. In distinction, armature side play is positively prevented by the armature mounting of the present invention, and the screw 54 may therefore be quickly adjusted within relatively Wide tolerable limits without detriment to the assembly. For example, in the specific embodiment illustrated herein, the screw 54 is simply threaded down to bring its base wall into engagement with the top of the respective ball 56 and is then simply backed off a quarter turn. On the other hand, if desired, the screw could be more carefully adjusted substantially to eliminate end play as well as side play of the armature. After adjustment, the screw 54 is preferably locked in place by means of cement or the like. As adjusted according to the specific embodiment hereof, the pivot structure defines two circular lines and one point (the end of one ball) of bearing contact, thereby to minimize friction in the pivot. Further to minimize friction, to insure precision fit of the parts, to mitigate wear and to provide a sturdy construction, We prefer to form the components of the armature mounting, i.e., the bracket, the balls, the end plate and the screw, from stainless steel.

As thus far constituted, an exceptionally stable, sturdy, and compact relay structure is afforded. The several components are integrated, and there is no danger of relative movement of the parts, except for the intended movement of the armature. The armature is firmly retained on a fixed pivot axis by the sockets and the balls, and the described assembly prevents side play of the armature. Consequently, the structure mitigates spurious movement of the armature even at high pulsing rates and under shock, vibration and sharp acceleration and de-acceleration.

In addition to the above described integration of parts, the side surfaces of the depending legs 32 of the yoke 28 constitute mounting surfaces for the contact assemblies 22, thereby further to insure precise correlation and integration of the components of the relay. In particular, each contact assembly includes a side panel 58 of insulating material, the panel being accurately pierced at spaced locations for passage therethrough of mounting tabs formed integrally with the legs, the tabs being bent over the exterior surface of the panels fixedly to secure the panels to the outer surface of the respective legs. The contact assemblies are identical and each include a pair of movable contact carrying leaves 62, a pair of stationary contacts 64 and a coil terminal tab The leaves 62 are each comprised of a base portion 68 fixedly secured to the panel 58 and including an integral terminal tab, and a leaf portion disposed transversely of the base and extending upwardly therefrom to above the upper edge of the panel. The two leaves are mounted with the leaf portions thereof in spaced, substantially parallel, coextensive relation, and each leaf portion is given an initial set so that the upper ends of the same are normally biased away from one another and normally retained in separated condition due to their inherent resiliency.

The stationary contacts or are mounted in opposed relation to one another to the opposite sides of and ad jacent the upper ends of the leaf springs 62, and are each disposed normally to be engaged by a contact mounted on the juxtaposed surface portion of the adjacent one of the leaves. The panel 58 is notched at the upper edge thereof, and each stationary contact is adjustably carried by an L-shaped base member 70, one leg of which is secured to the back surface of the panel 58 and the other leg of which extends through the notch into proximate relation to the adjacent leaf 62. This latter leg is provided adjacent its outer end with a tapped bore, and each contact 64 comprises a stud having a micrometer thread threaded through the respective bore and having its end disposed for engagement by the contact carried by the respective leaf 62. Due to the bias of the leaves 62, engagement of a leaf carried contact with a stationary contact 64 is effected by the leaf, and the pressure of contact engagement is dependent upon the degree of set or bias of the leaf.

At the upper ends thereof, the leaves 62 of each contact assembly extend into the path of movement of the outer end portion of the adjacent lever arm 26 of the actuator 18. The outer end of each lever arm 20 is notched or bifurcated to define two legs between Which the upper ends of the respective leaves 62 are positioned. Preferably, a bead of glass or the like is provided at the outer end of each leg of the actuator to insulate the contacts from the armature assembly. The spacing between the legs of each lever arm is less than the spacing between the stationary contacts 64, so that said legs will retain one or the other of the leaf carried contacts in spaced relation to its stationary contact when the other leaf carried contact is permitted to engage its stationary contact. In particular, the pair of contacts initially in engagement are separated from one another before the other pair of contacts are permitted to engage.

After attachment of the contact assemblies to the remainder of the armature structure, the stationary contacts 64, due to their threaded mounting, may readily be adjusted to satisfy precise operating conditions or specifications. After adjustment, the threaded contact studs are suitably locked in place by means of cement or the like.

The degree of movement and the operating force of the armature, and thus of the actuator and movable contacts, is accurately governed by the means illustrated in FIGURE 2. As there shown, each pole piece 24 of the relay is provided with a bore opening to the face 16 thereof. One bore is adapted for reception of an armature biasing or return spring 72, and is tapped at its outer end for reception of a spring adjusting screw 74, the screw '74 being adjustable to set, in conjunction with the leaf springs 62, the magnetic force required to operate the relay. The bore in the other pole piece is tapped throughout its length for adjustable reception therein of a nonpermeable residual screw 75 having a micrometer thread. The screw 75 is adapted to be engaged by the armature in the operate position thereof and serves to space the armature from the faces 16 of the pole pieces to insure against magnetic locking of the armature in its make position. To limit movement of the armature away from the pole pieces, a pair of pivotally adjustable back stops 76 are mounted on the upper strap portion 39 of the yoke 28 to the sides of the armature opposite the pole faces lid.

In the foregoing, it is to be noted that the biasing force on the armature which moves the armature to the position shown in FIGURE 1 as the relay is deenergized, is provided by a single return spring member 72 acting on one end of the armature. As there illustrated, the spring member 72 moves the armature and actuator to permit engagement of the right hand lever spring (as shown in FIGURE 1) 62 with its contact 64, and to thereafter effect continued movement of the armature to move the actuator Contact finger 26 out of engagement with the one of the lever springs which is now in the make position. With reference to FIGURE 2, it will be apparent that the left hand spring on the opposite side of the relay is operative in a similar manner. As a result of the contact actuator finger 20 being out of contact with the one of the lever springs which is in the make position, any shock or vibration forces which might be experienced by the armature or actuator member will not be transmitted to the lever spring, and a more reliable contact operation is effected by the relay structure in environments of severe shock and acceleration forces.

In a similar manner, the armature and actuator members are Operative to move the actuator fingers out of contact with the one of the lever springs which is in the make position whenever the relay is energized.

The actuator finger which is in engagement with the one of the lever members which is in the break position (whether the relay is energized or deenergized) is pro vided with sufficient clearance so that minor excursions or movements of the actuator and armature may be experienced without effecting improper closure of the contacts.

Heretofore, the use of a single return spring was not considered practical due to the inherent limitations of the mounting for the armature. Now, due to the improved pivot construction afforded by the balls 56 and cylindrical sockets of this invention, side play of the armature is prevented and the armature is fixedly retained on a precisely located pivot axis irrespective of the forces thereon. Consequentl the armature biasing force may be concentrated in a single spring, and the space previously occupied by a second spring is utilized according to this invention for the adjustable residual screw 75. This reduces the number of parts required in the assembly and simplifies to a marked degree adjustment and calibration of the relay. In particular, only one spring adjustment is now necessar' as contrasted to the former practice of adjusting two springs and equalizing the forces exerted thereby.

By virtue of the adjutsments provided, every aspect of relay operation may be variably adjusted to satisfy a wide range of exacting specifications.

The coils 78 and 8t) employed in the relay of the present invention are generally conventional spool-type coils. The cores 12 and 14 are formed of permeable iron and each carry a pair of spaced annuluses or spool heads 82 formed of an insulating or plastic material, such as epoxy glass cloth. Each spool head is split radially thereof to permit the same to he slipped onto the shank of the corand the spool heads are abutted respectively against the lower edge of the pole piece 24 and the upper face of the flange 26 of the respective core. Disposed on the inner side of each of the spool heads 82 is a spool head washer 84, suitably formed of Mylar or the like. The central cylindrical portions of the cores 12 and 14 are suitably covered with insulation, preferably Mylar tape or like material. The coil spools as thus formed may be suitably wound with either conventional or heat resistant insulated wire according to standard procedure to provide coils adapted for various particular purposes. The two coils are interconnected at one terminal end, as is conventional, and the other terminals of the coil wire are secured, respectively, to the tabs 66 on the contact as sembly panels 58.

Upon energization of the coils 78 and St a magnetic path through the relay is established through the coil cores 12 and 14 and pole pieces 24, the lower strap 3%, the armature It and the air gaps between the ends of the armature and the pole faces 16, whereby a high degree of flux concentration is provided in said gaps. The flange means 26 provided on the coil cores 12 and 14, due to their intimate engagement with the lower strap 38, so enlarge and improve the magnetic path or circuit of the relay as to accommodate any one of, or any desired combination of, the features of marked reduction in coil size, greater uniformity of magnetic power and higher magnetic forces, operation at lower amperage, and increased sensitivity. This improvement, particularly in conjunction with the improved armature mounting and use of an armature formed of a material having a high coercive magneto-motive force (49% nickel and 51% iron), has resulted in initial pull characteristics 225% greater than heretofore achieved in relays of the described character. This affords greater reliability and more stable vibration characteristics, and thereby facilitates manufacture of relays to exacting specifications and tolerances by mass production methods. This latter advantage of the present invention is, of course, markedly enhanced by the structural relay assembly provided hereby.

Upon occurrence of predetermined current flow through the coils '78 and 80, as determined by the aforesaid adjustments, the armature is attracted toward the pole faces 16 of the cores i2 and M and is moved into engagement with the residual screw 75 against the urge of the armature biasing spring 72. Upon movement of the armature 10, the lever arms 29 of the actuator 18 engage the right-hand leaf spring 62 (as viewed in FIGURE 1) and moves the same to the left to thereby disengage the right-hand contact set and thereafter permit engagement of the lefthand contact set. A similar operation is effected in the contact sets in the other contact assembly.

Since engagement of the contacts is permissive, and contact engagement is retained by the spring force of the leaves 62, the occurrence of contact bounce is mitigated, and the leaf springs absorb shock and vibration to prevent accidental or unintentional separation of the engaged pairs of contacts. Accordingly, good electrical contact is assured and the contact assemblies are highly resistant to shock, vibration and acceleration.

Upon deenergization of the coil, the return sring 72 which was compressed now expands, and exerts a force which moves the armature in a direction to move the contact spring 62 which was in the make position, to the break position, and to permit the contact spring 62 which was in the break position to move into the make position. Since the contact spring of each set which was in the make condition tends to resist movement of the armature in such direction, and the contact spring which was in the break condition tends to assist the armature in its movement to its deenergized position, the resultant effect of the two contact springs in each set is of a minor nature, and the working force of the return spring 72 is used to accomplish the movement of the armature to its normal position with the relay deenergized. As noted heretofore, the strength of the return spring '72 is such as to move the associated contact finger out of contact with the lever spring which is in the make position, to thereby prevent transfer of shock and acceleration forces which the armature and actuator members may experience to the lever spring. Movement of the armature away from the pole faces 16 is positively limited by the back stops 76. Due to the springs, the armature mounting, the magnetic circuit and the residual screw, there is no tendency of the armature to become magnetically locked or otherwise stuck in its operated position.

In addition to the advantages pointed out hereinbefore, the relay or" the present invention readily lends itself to fabrication in extremely small sizes. Generally, it may be stated that the major horizontal axes, i.e., the axis along which the coil core axes lie and the axis upon which the axes of the contact assemblies lie, may be maintained fairly constant or uniform for many various installations for which the relay of the present invention is adapted. However, the length of the coils, and thus of the relay as a whole, in these instances may vary within quite substantial limits to accommodate the Winding of coils adapted for energization from various sources and power supplies. Variations in the physical dimensions and structure of the relay may be required in adapting the same to various installations, but the basic arrangement provided by the invention will be adhered to. Despite these variations, the adaptability of the relay of the present invention may cover a wide variety of installations, while the physical dimensions of the relay may vary only slightly, with the exception of its length.

For the variety of installations referred to, the relay may be mounted within any suitable container or casing for the particular installation at hand. In FIGURES 1 and 2, there is disclosed, by way of example, one suitable mounting for the relay. As there shown, the relay is mounted on a connector base with the lower plate 33 being received within the base and portions of the side wall of the base being bent over, as indicated at 88, to engage the upper surface of the plate 38 and secure the relay to the base. The base includes the customary pin connectors 99 from which leads are conducted to each of the spring leaves 52, the stationary contacts 64 and the coil terminals 66, thereby to facilitate connection of the relay to a source of power and a circuit or circuits to be controlled. The relay structure, being exceedingly compact, is adapted to be enclosed in a can to be hermeti ally sealed therein, the can (not shown) being slipped over the relay and the upper marginal portion of the base 86 and secured in sealed relation to the base. The base and can are preferably formed in such manner that the relay may conveniently be hermetically seal d therein. By suitable selection of the material of the base 3 3 and the can, the enclosure may serve various purposes. For example, by forming the enclosure elements of brass, the same will comprise a magnetic shield for the relay to prevent influence of the relay from extraneous magnetic fields.

In a specific embodiment of the relay of the invention, in the 20 to 40 milliwatt class, we have hermetically sealed the relay within a can 1% inches long and .97 inch square. Contact gaps are a minimum of .004 inch and contact pressure is in the order of 20 grams plus or minus 2 grams. Armature play is a maximum of .003 inch and the force of the armature on its back stops, due to spring pressure, is preferably within the range of 20 to 30 grams. The coils have a DC. resistance of 12,000 ohms plus or minus 10%. The requirements imposed were a pull-in current of 1.3 milliarnps maximum and a dropout current of .45 milliarnp minimum over a temperature range of degrees C. to degrees C. Over that range of temperatures, the relay had a pull-in current range of 1.14 milliamps to 1.25 milliamps, and a drop-out current range of .55 milliamp to .72 milliamp. Relative to resistance to vibration, shock and accelerative forces, the most stringent requirements imposed are a maximum contact opening period of 10 microseconds for vibrations from 0 to 3,000 cycles per second and accelerative forces in the order to 50 gravity units. Under test, the specific relay had a maximum contact opening of 5 microseconds at resonance and no openings at other frequencies. The contact structures proved substantially bounce free. Operate time is 50 milliseconds maximum, and release time is 2 milliseconds maximum. The relay thus satisfies all of the above-stated requirements and affords an improved relay structure particularly adapted to manufacture on a mass production basis.

It is understood, of course, that the above description of a specific relay has been given for exemplary purposes simply to illustrate the degree of sensitivity and temperature range of operability and other similar details of the relay of the invention. Although the lower ends of the two contact springs 62 are shown connected by a strap to provide a common output circuit, it will be appreciated that separate circuits may be provided by removing the strap and connecting signal output leads to the two contact springs 62. Thus, the basic relay structure is sufiiciently flexible to permit utilization of the relay in vastly different applications and to provide relays of widely difierent specifications without departing from the scope of the invention.

Contact switching functions As noted heretofore the novel relay structure is such that a plurality of different types of switching functions may be accomplished with the illustrated structure by effecting adjustment of the various members to correspondingly different relative positions. In the arrangement shown in FIGURE 1, for example, the actuator fingers 3.0 are adjusted relative to the ends of the contact springs 62 and the stationary contacts s4 are so positioned as to provide an arrangement which is known in the art as a break-before-make contact structure. As there shown, with the relay deenergized, the actuator finger 20 on each side of the relay operates the one contact spring 62 out of engagement with its associated contact 64 (the break contact), and the bias of the second contact spring 62 efifects movement thereof into engagement with contact 64 (the make contact).

As the relay is energized and the armature (as shown in FIGURE 1) moves the actuator 18 in a clockwise direction; shown in FIGURE 2, the right hand actuator finger moves to the left as shown in FIGURE 1, to move the right hand contact spring out of engagement with its associated stationary contact 64 and with further armature movement left hand actuator finger 20 permits the left hand contact spring 62 to move into contact with its associated stationary contact The contact set on the opposite side of the relay is adjusted in a similar manner, and accordingly a "break-before-make condition is provided for the contacts of both sets. The relay structure of FIGURE 1 may be defined by the expression A B, C D, A=C, and B=D, wherein A is the spacing between actuator arm 200 (see FIGURE 6A) and contact spring 62a, B is the distance between the con tact on spring 62b and contact ddb, C is the distance between contact spring 620 and actuator finger 20c, and D is the distance between the contact on spring 62d and contact 64d.

With reference now to FIGURES 61 421), there is shown thereat the manner in which the positions of the different members such as the fingers 20 of the actuator member 118, the contact spring 62, the stationary contact etc., may be adjusted relative to each other to provide (a) a make-before-arrangement for a first contact set disposed on one side of the relay and also for a second contact set disposed on the other side of the relay, the contact sets on each side of the relay being operated concurrently (FIGURE 6A); (b) a first and a second contact structure, each of which provides a break-beforemake switching function, the first contact set effecting such operation prior to such operation by the second contact set of the relay (FIGURE 63); (c) a first and a second contact structure, one of which is adjusted to provide a break-before-make contact switching operation and the other of which is adjusted to provide a make-before-break switching operation, the switching operation by the one contact set being effected prior to the switching operation by the other contact set (FIGURE 6C); and (d) a first and a second contact structure, each of which is adjusted to provide a make-before-break switching operation, the switching operation being effected by the first contact set prior to the switching operation by the second contact set. Other manners of adjustment to effect further types of switching functions which are characterized by the accomplishment of switching operations by different contact sets at correspondingly different time periods will be evident from the detailed description of the disclosed arrangements which is now set forth hereat.

It should be understood with reference to FIGS. 6A6D that the contacts are shown off-set from the ends of the 10 actuator arms for clarity, but should be considered in line with them as per FIG. 2.

First and second contact set concurrently operative to provide "ntake-bcforc-brcak switching operations With reference to FIGURE 6A, the relay structure members which are basic to the provision of a first and a second make-before-break contact switching operations are set forth schematically thereat. As there shown, the relay is in the rile-energized position, and return spring '71. is biassing the armature 10 against the stop members 7a. In the first contact set at the top of FEG. 6A, the actuator finger 20a is moved out of engagement with its associated contact spring 62a, and the biasing force of the contact spring 62a has moved itself and the contact mounted thereon so that the movable contact has come into contacting relation with the adjacent stationary contact 64a. Additionally, actuator finger 20]; at the top of FIG. 6A engages contact spring 6211 to move the contact mounted thereon out of contact with its associated stationary contact 641;. In the second contact set, the actuator finger 20c is moved out of engagement with the contact spring 62c, and the biassing force of the contact spring 62c moves the contact mounted thereon into contacting relation with the adjacent stationary contact 64c. Additionally actuator finger 20d engages contact spring 62d to move the contact mounted thereon out of contact with the associated contact 64d.

In the illustrated example, the different members operative in the switching function are adjusted relative to each other so that the contact on leaf spring 62b and stationary contact 64b are separated by a distance of .004 inch; the actuator finger 20a is separated from the leaf spring 62a by a distance of .006 inch; contact finger Eric is separated from its adjacent leaf spring 620 by a distance of .006 inch, and the contact on leaf spring 62d and the stationary contact 64d are separated by a distance of .004 inch.

As the relay is energized, and the armature is moved in a clockwise direction against the force of return spring 72, the armature in its initial movement permits the contact on spring 62b to engage adjacent stationary contact 64b (.004 spacing), and simultaneously contact finger 20d permits the contact on spring 62d to engage its adjacent stationary contact 64d (.004 spacing). At this instant, each of the circuits controlled by contacts 62b, 64b, and contacts @211, 64d, have been completed and since the actuator fingers 20a and 200 have not as yet moved into contact with contact springs 62a and 620 respectively, the contacts controlled thereby will also be in the closed or make position.

With continued movement of the armature in a clockwise direction, the actuator fingers 20a, 20c engage the upper ends of leaf springs 62a and 620 respectively (spacing .006) to move the contacts thereon out of engagement with the associated stationary contacts 64a, 64c respectively to thereby operate the contacts to the break or open condition. It is apparent from the foregoing description that a make-before-break condition is effected concurrently in the two contact sets which are located on either side of the relay structure Summarily the relay structure may be defined by the expressions B A, D C, A 6 and B D, wherein A, B, C and D are the spacings identified in the expressions set forth previously herein.

First and second contact sets for providing break-beforemakc switching functions at time-spaced intervals With reference now to FIGURE 63, it will be apparent that the different members which are basic to the switching operation are adjusted to provide a spacing of .003 inch between actuator finger 20a and contact spring 62a; a spacing of .005 inch between the contact on spring 62b and stationary contact 6412, a spacing of .007 inch between contact spring tiZc and actuator finger 20c, and a ls l spacing of .009 inch between the contact on spring 62d and stationary contact 640.. It is apparent therefrom that with the relay deenergized contacts 62a, 64:: are closed; contacts 62b, 64b are open; contacts 620, 64c, are closed; contacts 62d, 6 rd are open; and that fingers a and 200 are disengaged from their associated contact springs.

With encrgization of the relay and movement of the armature in a clockwise direction, actuator finger 2% will be first brought into contact with the upper end of contact spring 62a (spacing .003) to eifect opening of contacts 62a, 64a, and thereafter with the further travel of the armature the actuator finger 20b permits movement of the contact on spring 62b into engagement with the adjacent stationary contact 64b (spacing .005); and with further armature movement, actuator finger 20c will be brought into contact with the end of contact spring 620 (.007 spacing) to urge the contact thereon out of engagement with stationary contact 64c, and with further movement of the armature, the actuator finger 20d permits movement of the contact on spring 62d into engagement with the stationary contact o t-d (.009 spacing). With further movement of the armature to its extreme position the actuator finger 2012 is moved out of contact with the leaf spring 62d. It should be appreciated that with further clockwise movement of the actuator after contacts bib-64b close, actuator finger 20b moved out of engagement with contact spring 62b.

summarily, the one contact set effects a break-befor rnake switching function during the first movement of the armature, and with a subsequent additional movement of the armature, the second contact set effects a second break-before-make switching function. Thus two separate break-before-make switching functions are accomplished by the relay at different spaced time intervals responsive to a single operation of the relay armature member. The relay structure of FIGURE 68 may be defined by the expression A B C D, wherein A, B, C and D are the spacings identified in the expressions set'forth above.

A break-before-make switching operation by a first contact set followed by a make-before-break switching operation by a second Contact set With reference to FIGURE 6C, the members essential to the switching functions of the relay are adjusted so that the actuator finger 20a is spaced from the contact spring 621a by a distance of .003 inch; the contact on spring 62!) spaced from the stationary contact 64b by a distance of .005 inch; contact spring 620 is spaced from actuator finger 200 by a distance of .007 inch, and the contact on spring 62d is separated from stationary adjacent contact 64d by a distance of .006 inch.

With energization of the relay, and movement of the armature in a clockwise direction, the relative adjustment of such members will result in the opening of contacts 62a and 64a by actuator finger 20a (.003 spacing) and with further movement of the armature, actuator finger 20b will permit the closure of contacts 62b and 64b (.005 spacing). An additional movement of the armature is elfected, actuator finger permits closure of contacts 62d and 64d (.006 spaci; and thereafter actuator finger 20c effects opening of contacts 620 and 640 (.007 spacing). With the armature actuator in the extreme clockwise position, actuator fingers 20d and 20b will be found moved out of engagement with the contact spring members 62d respectively.

Summarily, the relay arrangement of FIGURE 6C in its operation controls the one contact set to effect a breakbefore-make switching function, and thereafter with continued movement of the armature controls the second contact set to effect a make-before-break switching function. The relay strucure may be defined by the expreession A B D C, wherein A, B, C, D are the spacings identifled in the expressions set forth above.

12 A makebefore-break switching operation by a first colitact set followed by a make-before-break switching operation by a second Contact set With reference to riuURE 6D, the arrangement is adjusted to provide a make-before-break switching function by a first and by a second contact set, the switching functions being provided at successive, ditl'erent time periods.

As there shown, the members which are basic to the switching operation are adjusted so that the contact finger is separated from the contact spring 62a by a distance of .006 inch; the contact on spring 62b and Contact 641) are separated by a distance of .004 inch; actuator finger 200 is separated from contact spring 62c by a distance of .008 inch; and the contact on spring 62a and contact 64d are separated by a distance of .007 inch.

in operation with energization of the relay, and movement of the armature in a clockwise direction, the actuator finger 20b is first operative to permit closure of contacts 32b and dab (.004 in spacing) and with continued movement of the armature, actuator finger 20a effects opening of contacts 62a and 64a. With further movement of the armature, actuator finger 200. permits closure of contacts 62d and (.007 in spacing) and with further movement actuator finger 20c engages contact spring 62c (.008 in spacing) to effect opening of contacts 620 and 640. With the armature in its extreme operated position, the actuator fingers 20d and 20b have been moved out of engagement with the contact springs 62d and 62b respectively.

Summarily, with operation of the relay armature, the actuator operates a first and a second contact set to effect a first and a second make-before-break switching function, the first contact set being operative to effect the switching function at a time period prior to the switching operation effected by the second contact set. The relay structure of FIGURE 63) may be defined by the expression B A D C in which A, B, C, D are the spacings identified in the expressions for the other relay structures above.

The foregoing switching arrangements set forth in F1"- URIES 6A-6D have been provided for exemplary purpose, and it is noted once more that the values set forth thereat have been selected only for exemplary purposes, and are not to be considered limiting. It is apparent that a plurality of further switching functions which differ by reason of the respective time intervals of occurrence, may be effected by providing adjustments of the various members essential to the switching operation in a corresponding manner, and such modifications are considered to be within the scope of the invention.

From the foregoing, it will be appreciated that the present invention provides an improved relay of extremely practical and economical construction and assembly that is adapted to be readily actuated in response to energization, but which will not be actuated by, or be responsive to, vibration, shock, and accelerative forces. It will be appreciated, also, that the invention provides an extremely compact relay adapted for a variety of uses and installations. In particular, it will be appreciated that the present invention provi es an improved structural assembly for relays including an improved pivot structure, an improved spring and residual means for use in combination with said pivot structure, and improved contact means for relays of the described character. The structural assembly described, together with the improved magnetic circuit, especially facilitates mass production of relays to the most exacting specifications.

It is further apparent that by practicing the expedient of adjusting the position of various ones of the members such as the stationary contact member of each contact assembly, the armature backstops, the contact springs, the actuator finger, the residual screws, and the spring tensions of the contact springs and the return spring, and others, the relay structure may be utilized in an extremely large number of varied and different applications.

While we have shown and described what we regard to be the preferred embodiment of our invention, it will be appreciated that various changes, rearrangements and modifications may be made therein without departing from the scope of the invention, as defined by the apended claims.

We claim:

l. A relay structure comprising, in combination, a pivotally movable armature balanced relative to its pivot axis, a contact actuator secured to said armature and balanced relative to the pivot axis thereof, and a pair of contact assemblies, one assembly being located at each side of said armature, each assembly including a pair of opposed stationary contacts and a pair of spring contact leaves disposed between said stationary contacts and normally biased toward engagement with the adjacent contact, said actuator at each end thereof including a bifurcated portion each bifurcation of which is disposed to the side of a respective one of said spring leaves adjacent its stationary contact, said armature and said actuator normally retaining one spring leaf of each assembly in spaced relation to its adjacent stationary contact and permitting engagement of the other spring leaf of each assembly with its adjacent stationary contact by its own bias.

2. A relay structure comprising, in combination, a pair of spaced parallel coil cores each having flange means adjacent the lower end thereof, a permeable lower strap secured to and interconnecting the lower end portions of said cores and abutted tightly against the lower surfaces of said flange means, and a yoke including an upper strap portion secured to and interconnecting said cores adjacent their upper ends, said yoke including a pair of depending portions extending downwardly from said upper strap portion to said lower strap and fixedly secured at their lower ends to said lower strap, whereby structural stability is assured, said flange means also enlarging the flux transfer path between each core and said lower strap.

3. A relay structure comprising, in combination, a pair of spaced parallel coil cores defining a pair of poles adjacent their upper ends, a lower strap secured to and interconnecting the lower end portions of said cores, a yoke including an upper strap portion secured to and interconmeeting said cores immediately below said poles, said yoke including a pair of depending portions extending downwardly from said upper strap portion to said lower strap and fixedly secured at their lower ends to said lower strap, an armature mounting bracket fixed to one of said poles above said upper strap portion, and an armature pivotally mounted on said bracket for movement toward and away from said poles.

4. A relay structure comprising, in combination, a pair of spaced parallel coil cores defining a pair of poles adjacent their upper ends, each of said cores having permeable flange means adjacent the lower end thereof, a permeable lower strap secured to and interconnecting the lower end portions of said cores and abutted tightly against said flange means, a yoke including an upper strap portion secured to and interconnecting said cores immediately below said poles, said yoke including a pair of depending portions extending downwardly from said up per strap portion to said lower strap and fixedly secured at their lower ends to said lower strap, an armature mounting bracket secured to one of said poles above said upper strap portion and including spaced upper and lower portions extending into the space between said poles, the lower portion of said bracket having a cylindrical socket therein, a screw threaded through the upper portion of said bracket and having a cylindrical socket therein, said sockets defining a pivot axis parallel to and midway between the axes of said cores, a permeable armature having a pair of balls secured to the upper and lower surfaces thereof which balls are positioned in said sockets to pivotally mount said armature with the end portions the'eof juxtaposed, relative to said poles, a contact assembly mounted on each of said depending portions, each contact assembly including a pair of movable contact springs and a pair of stationary contacts, the contact springs being biased away from each other and toward their respective stationary contacts, and actuator means secured to said armature to normally retain one contact spring of each assembly in spaced relation to its stationary contact, and permitting the other contact spring of each assembly to engage its stationary contact.

5. A relay structure comprising, in combination, a pivotally movable armature balanced relative to its pivot axis, a contact actuator secured to said armature and balanced relative to the pivot axis thereof, and a pair of contact assemblies, each assembly being disposed on one side of said armature, each assembly including a pair of opposed stationary contacts and a pair of contact springs disposed between said stationary contacts each of which is normally biased toward engagement with its adjacent stationary contact, said armature and said actuator being disposed to normally retain one contact spring of each assembly in spaced relation to its adjacent stationary contact and to permit engagement of the other contact spring of each assembly with its adjacent stationary contact by its own bias.

6. A relay structure comprising, in combination, a pivotally movable armature balanced relative to its pivot axis, a contact actuator secured to said armature and balanced relative to the pivot axis thereof, and a contact assembly disposed on each side of said armature, each assembly including a pair of opposed stationary contacts and a pair of contact springs disposed between said stationary contacts and normally biased toward engagement with the adjacent stationary contact, said armature and said ac tuator being disposed to normally retain one contact spring of each assembly in spaced relation to its adjacent stationary contact and to permit engagement of the other contact spring of each assembly with its adjacent stationary contact, said actuator being operative with a given movement of said armature to permit movement of said one contact spriri in at least one contact assembly into engagement with its adjacent stationary contact, by its own bias and to thereafter efiect movement of the other contact spring of said one assembly out of engagement with its adjacent stationary contact.

7. A relay structure comprising, in combination, a pivotally movable armature balanced relative to its pivot axis, a contact actuator secured to said armature and balanced relative to the pivot axis thereof, and a pair of contact assemblies, one assembly being disposed on each side of said armature, each assembly including a pair of opposed stationary contacts and a pair of contact springs disposed between said stationary contacts and normally biased toward engagement with the adjacent stationary contact, said armature and said actuator being disposed to normally retain one contact spring of each assembly in spaced relation to its adjacent stationary contact and to permit engagement of the other contact spring of each assembly with its adjacent stationary contact, said actuator being operative with a given movement of the armature to effect movement of said other contact spring in one contact assembly, at least, out of engagement with its adjacent stationary contact, and thereafter to move out of engagement with one contact spring to permit the bias of said one contact spring in said one assembly to move said one contact spring into engagement with its adjacent stationary contact.

8. A relay structure comprising, in combination, a pivotally movable armature balanced relative to its pivot axis, a contact actuator secured to said armature and balanced relative to the pivot axis thereof, a first contact assembly disposed on one side of said armature and a second contact assembly disposed on the opposite side of said armature, each assembly comprising at least a stationary contact and a contact spring which are operative into an open and closed condition with each other, the contact spring being biased toward engagement with the adjacent stationary contact, said armature and said actuator normally retaining the contact spring and stationary contact of one assembly in one of said conditions, and permitting the contact spring and stationary contact of the other assembly to operate to the other of said conditions, and being operative with movement of the armature to permit operation of the contact spring and stationary contact of said one assembly to the other of said conditions, and thereafter to eifect operation of the contact spring and stationary contact of said other assembly to said one condition, the bias of the contact spring in each assembly etfecting said operation of its assembly to said other condition.

9. A relay structure comprising, in combination, a pivotally movable armature balanced relative to its pivot axis, a contact actuator secured to said armature and balanced relative to the pivot axis thereof, and a pair of contact assemblies, one assembly disposed on each side of said armature, each assembly including a pair of opposed stationary contacts and a pair of contact springs disposed between said stationary contacts, each contact spring being normally biased toward engagement with its adjacent stationary contact, said armature and said actuator being disposed to normally retain one contact spring of each assembly in spaced relation to its stationary contact and to permit engagement of the other contact spring of each assembly with its adjacent stationary contact by its own bias, said actuator being operative with movement of the armature to permit the engagement of the one contact spring with its stationary contact by its own bias and the disengagement of the other contact spring with its stationary contact, the op eration of the contact springs in the different contact assemblies being effected at different, successive time intervals.

10. A relay structure comprising, in combination, a pivotally movable armature balanced relative to its pivot axis, a contact actuator secured to said armature and balanced relative to the pivot axis thereof, and a pair of contact assemblies, one assembly being disposed on each side of said armature, each assembly including a pair of opposed stationary contacts and a pair of contact springs disposed between said stationary contacts, each of which is normally biased toward engagement with its adjacent stationary contact, said armature and said actuator being disposed to normally retain one contact spring of each assembly in spaced relation to its stationary contact and to permit engagement of the other contact spring of each assembly with its stationary contact by its own bias, said actuator being operative with movement of said armature to effect in one contact assembly the disengagement of the other contact spring with its adjacent stationary contact and thereafter to permit engagement of the one contact spring with its adjacent stationary contact by its own bias, and at a later time interval to effect in the other contact assembly the disengagement of the other contact spring with its adjacent stationary contact, and thereafter to permit engagement of the one contact spring in said other contact assembly with its adjacent stationary contract by its own bias.

11. A relay structure comprising, in combination, a pivotally movable armature balanced relative to its pivot axis, a Contact actuator secured to said armature and balanced relative to the pivot axis thereof, and a contact assembly disposed on each side of said armature, each assembly including at least a stationary contact and a contact spring which are operative between an open and closed condition with each other, and in which the contact spring is biased toward engagement with the adjacent stationary contact, said armature and said actuator normally retaining the contact and stationary contact of each of said assemblies in one of said conditions and said actuator being operative with movement of the armature n to to permit operation of the contacts of one of said assemblies to the other condition, by the bias of its contact spring and thereafter the contacts of the other of said assemblies to the other condition by the bias of its contact spring.

12. A relay structure comprising, in combination, a pivotally movable armature balanced relative to its pivot xis, a contact actuator secured to said armature and balanced relative to the pivot axis thereof, and a contact assembly disposed on at least one side of said armature including a pair of :opposed stationary contacts and a pair of contact springs disposed between said stationary contacts, each of which is normally biased toward engagement with its adjacent stationary contact, said armature and said actuator being disposed to normally retain one contact spring of each assembly in spaced relation to its adjacent stationary contact, and to permit engagement of the other contact spring of each assembly with its adjacent stationary contact, by its own bias said armature and acuator being operative with movement thereof to open the closed ones of the contacts and to permit closure of the open ones of the contacts by their own bias at difierent, successive time periods.

13. A relay structure comprising, in combination, a pair of spaced parallel coil cores defining a pair of poles adjacent their upper ends, a lower strap secured to and interconnecting the lower end portions of said cores, a yoke including an upper strap portion secured to and interconnecting said cores immediately below said poles, said yoke including a pair of depending portions extending downwardly from said upper strap portion to said lower strap and fixedly secured at their lower ends to said lower strap, an armature mounting bracket secured to one of the said poles above said upper strap portion and including spaced upper and lower portions extending into the space between said poles, the lower portion or" said bracket having a cylindrical socket therein, a screw threaded through the upper portion of said bracket and having a cylindrical socket therein, said sockets defining a pivot axis parallel to and midway between the axes of said cores, and an armature having a pair of balls secured to the upper and lower surfaces tnereof which balls define a pivot axis located centrally of the armature, said balls being intimately journall d respectively in said sockets and pivotally mounting said armature on said bracket in statically and dynamically balanced condition with the end portions thereof juxtaposed to said poles, said balls and sockets retaining said armature against side play for movement about a fixed pivot axis.

14. A relay structure comprising, in combination, a pair of spaced parallel coil cores defining a pair of poles adjacent their upper ends, each of said cores having permeable flange means adjacent the lower end thereof, a permeable lower strap secured to and interconnecting the lower end portions of said cores and abutted tightly against said flange means, a yoke including an upper strap portion secured to and interconnecting said cores immediately below said poles, said yoke including a pair of depending portions extending downwardly from said upper strap portion to said lower strap and fixedly secured at their lower ends to said lower strap, whereby to assure structural stability, an armature mounting bracket secured to one of said poles above said upper strap portion and including spaced upper and lower portions extending into the space between said poles, the lower portion of said bracket having a cylindrical socket therein, a screw threaded through the upper portion of said bracket and having a cylindrical socket therein, said sockets defining a pivot axis parallel to and midway between the axes of said cores, and a permeable armature having a pair of balls secured to the upper and lower surfaces thereof which balls define a pivot axis located centrally of the armature, said balls being positioned respectively in said sockets and pivotally mounting said armature on said bracket in statically and dynamically balanced condition with the end portions thereof juxtaposed to said poles, said poles, said cores, said flange means and said armature defining a flux circuit of high capacity.

15. A relay structure comprising, in combination, a pair of spaced parallel coil cores defining a pair of poles adjacent their upper ends, a lower strap secured to and interconnecting the lower end portions of said cores, a yoke including an upper strap portion secured to and interconnecting said cores immediately below said poles, said yoke including a pair of depending portions extending downwardly from said upper strap portion to said lower strap at the opposite sides of and in spaced parallel relation to the plane of the axes of said cores, said depending portions being fixedly secured at their lower ends to said lower strap, a contact assembly mounted on the outboard surface of each of said depending portions, the vertical axes of said assemblies being disposed in a common plane extending centrally between the axes of said cores, an armature mounting bracket secured to one of said poles above said upper strap portion and including portions extending into the space between said poles, an armature pivotally mounted on said bracket on a pivot axis coincident with the line of intersection of the plane of the axes of said cores and the plane of the vertical axes of said assemblies, and a contact actuator secured to said armature with its vertical axis coincident with the pivot axis of said armature, said actuator including balanced arms extending outwardly from said armature to said contact assemblies for actuating the same in response to movement of said armature.

16. A relay structure comprising, in combination, a pair of spaced parallel coil cores defining a pair of poles adjacent their upper ends, a lower strap secured to and interconnecting the lower end portions of said cores, a yoke including an upper strap portion secured to and in terconnecting said cores immediately below said poles, said yoke including a pair of depending portions extending downwardly from said upper strap portion to said lower strap at the opposite sides of and in spaced parallel relation to the plane of the axes of said cores, said depending portions being fixedly secured at their lower ends to said lower strap, a contact assembly mounted on the outboard surface of each of said depending portions, the vertical axes of said assemblies being disposed in a common plane extending centrally between the axes of said cores, each assembly including a pair of contact carrying movable spring leaves disposed equal distances to the opposite sides of the vertical axis of the assembly and stationary contact means to be engaged thereby, said spring leaves being normally biased away from one another and toward their respective stationary contact means, an armature mounting bracket secured to one of said poles above said upper strap portion and including spaced upper and lower portions extending into the space between said poles, the lower portion of said bracket having a socket therein, a screw threaded through the upper portion of said bracket and having a socket therein, said sockets defining a pivot axis coincident with the line of intersection of the plane of the axes of said cores and the plane of the vertical axes of said assemblies, an armature having a pair of balls secured to the upper and lower surfaces thereof which balls define a pivot axis located centrally of the armature, said balls being positioned respectively in said sockets and pivotally mounting said armature on said bracket in statically and dynamically balanced condition with the end portions thereof juxtaposed to said poles, and a contact actuator secured to said armature with its vertical axis coincident with the pivot axis of said armature, said actuator including balanced arms extending outwardly from said armature toward said contact assemblies, each of said arms including a bifurcated outer end portion the bifurcations of which are adapted to engage the surface of the respective one of said spring leaves that faces toward its respective stationary contact means, said armature and said actuator normally retaining one spring leaf of each contact assembly in spaced relation to its stationary contact means and permitting the other spring leaf of each assembly to engage its respective contact means.

17. A relay structure comprising, in combination, a pair of spaced parallel coil cores defining a pair of poles adjacent their upper ends, a lower strap secured to and interconnecting the lower end portions of said cores, a yoke including an upper strap portion secured to and interconnecting said cores immediately below said poles, said yoke including a pair of depending portions extending downwardly from said upper strap portion to said lower strap at the opposite sides of and in spaced parallel relation to the plane of the axes of said cores, said depending portions being fixedly secured at their lower ends to said lower strap, a contact assembly mounted on the outboard surface of each of said depending portions, the vertical axes of said assemblies being disposed in a common plane extending centrally between the axes of said cores, each assembly including a pair of contact carrying movable spring leaves disposed equal distances to the opposite sides of the vertical axis of the assembly and stationary contact means to be engaged thereby, said spring leaves being normally biased by virtue of their inherent resiliency away from one another and toward their respective stationary contact means, an armature mounting bracket secured to one of said poles above said upper strap portion and including spaced upper and lower portions extending into the space between said poles, the lower portion of said bracket having a cylindrical socket therein, a screw threaded through the upper portion of said bracket and having a cylindrical socket therein, said sockets defining a pivot axis coincident with the line of intersection of the plane of the axes of said cores and the plane of the vertical axes of said assemblies, an armature having a pair of balls secured to the upper and lower surfaces thereof which balls define a pivot axis located centrally of the armature, said balls being intimately journalled respectively in said sockets and pivotally mounting said armature on said bracket in statically and dynamically balanced condition with the end portions thereof juxtaposed to said poles, said balls and sockets retaining said armature against side play, said poles having apertures therein, an armature biasing spring positioned in the aperture in one of said poles and engaging the adjacent end of said armature for normally spacing said armature from said poles, screw means for adjusting said spring, backstop means mounted on the upper strap portion of said yoke and including portions engageable by said armature for limiting movement thereof away from said poles, a residual screw adjustably mounted in the aperture in the other of said poles and projecting a short distance beyond the face thereof juxtaposed to the adjacent end portion of the armature for preventing engagement of the armature and said poles and magnetic locking of the armature, a contact actuator secured to said armature with its vertical axis coincident with the pivot axis of said armature, said actuator including balanced arms extending outwardly from said armature toward said contact assemblies, each of said arms including a bifurcated outer end portion the bifurcations of which are adapted to engage the surface of the respective one of said spring leaves that faces toward its respective stationary contact means, said armature and said actuator normally retaining one spring leaf of each contact assembly in spaced relation to its stationary contact means and permitting the other spring leaf of each assembly to engage its respective contact means, and a screw for adjustably setting each of said stationary contact means relative to the respective spring leaf.

18. In a relay having a pair of spaced parallel poles and an armature mounted for pivotal movement toward and away from the poles about a pivot axis disposed midway between and parallel to the poles, the improvement comprising, in combination, a bracket including spaced parallel mounting portions extending into the space between the poles, one of said portions having a cylindrical socket therein, a screw adjustably mounted in the other or said portions and having a cylindrical socket therein, said sockets facing toward one another and being aligned with one another along an axis disposed midway between and parallel to the poles, a pair of balls secured to the opposite sides of the armature and intimately journalled respectively in said sockets, said balls and sockets retaining the armature against side play and said screw controlling end play thereof, each of the poles having a bore wherein generally normal to the armature, a spring in one of said bores engaging the armature and normally biasing the same away from the poles, and a residual in the other of said bores and projecting slightly from the face of the respective pole for preventing engagement of the armature with the poles.

19. In a relay having a pivotally movable armature means, the improvement comprising a mounting bracket for said armature means including a pair of space parallel mounting portions located on either side of the armature means, one of said portions including a pivot structure for the armature means at one side thereof including a first adjustably mounted screw element having a first cylindrical socket therein, a first ball fixedly secured to said one side of said armature means and intimately journailed within the first cylindrical socket, the depth of the cylindrical socket being less than the distance the ball projects above the side of the armature adjacent the socket, and being greater than the radius of the ball to maintain the major portion of the ball within said socket and in line contact journalled relationship at its circumference with the surrounding wall of said socket, said second portion including a pivot structure for the other side of the armature means comprising an element having a second cylindrical socket therein aligned with said first cylindrical socket, and a second ball fixedly secured to said other side of said armature means and intimately journalled in said second cylindrical socket, the depth of the second cylindrical socket being less than the distance the second ball projects above the side of the armature adjacent the socket, and being greater than the radius of the ball to maintain the major portion of the ball within said second socket and in line contact journalled relationship at its circumference with the surrounding wall of said second socket, said adjustable screw element including said first cylindrical socket being adjustable along the axis of said sockets to determine allowable end play of said armature means without resultant side play of the armature means.

References Cited by the Examiner UNITED STATES PATENTS 451,808 5/91 Cooper 308159 701,499 6/02 Norstr-om 200-98 987,192 3/11 Turbayne 20098 1,763,003 6/30 Norstrom 317-197 1,770,673 7/30 Shaw 200-404 1,785,702 12/30 Osborne 200-87 2,281,671 5/42 Brown 308159 2,351,588 6/44 Field 20087 2,353,756 7/44 Price 200104 2,428,218 9/47 Herbst 20087 2,455,049 11/48 Edwards et al. 200-87 2,472,709 6/49 Knapp -2 200-104 2,760,026 8/56 Horlacher 317-498 2,767,280 10/56 Hall et al. 200-87 2,810,037 10/57 Fans et al. 317198 2,824,189 2/58 Zimmer 200-87 2,844,685 7/58 Bydalek et al. 20087 2,881,281 4/59 Sprando 200--87 2,882,367 4/59 Baker et al. 20087 2,923,794 2/60 Keeran 20087 2,934,621 4/60 Stewart 2O0-87 2,937,249 5/60 Obszarny et al. 20087 2,951,134 8/60 Lazich 200104 2,959,648 11/60 Williams 200-87 ROBERT K. SCHAEFER, Acting Primary Examiner.

MAX L. LEVY, RICHARD M. WOOD, Examiners. 

13. A RELAY STRUCTURE COMPRISING, IN COMBINATION, A PAIR OF SPACED PARALLEL COIL CORES DEFINING A PAIR OF POLES ADJACENT THEIR UPPER ENDS, A LOWER STRAP SECURED TO AND INTERCONNECTING THE LOWER END PORTIONS OF SAID CORES, A YOKE INCLUDING AN UPPER STRAP PORTION SECURED TO AND INTERCONNECTING SAID CORES IMMEDIATELY BELOW SAID POLES, SAID YOKE INCLUDING A PAIR OF DEPENDING PORTIONS EXTENDING DOWNWARDLY FROM SAID UPPER STRAP PORTIONS TO SAID LOWER STRAP AND FIXEDLY SECURED AT THEIR LOWER ENDS TO SAID LOWER STRAP, AN ARMATURE MOUNTING BRACKET SECURED TO ONE OF THE SAID POLES ABOVE SAID UPPER STRAP PORTION AND INCLUDING SPACED UPPER AND LOWER PORTIONS EXTENDING INTO THE SPACE BETWEEN SAID POLES, THE LOWER PORTION OF SAID BRACKET HAVING A CYLINDRICAL SOCKET THEREIN, A SCREW THREADED THROUGH THE UPPER PORTION OF SAID BRACKET AND HAVING A CYLINDRICAL SOCKET THEREIN, SAID SOCKETS DEFINING A PIVOT AXIS PARALLEL TO SAID MIDWAY BETWEEN THE AXES OF SAID CORES, AND AN ARMATURE HAVING A PAIR OF BALLS SECURED TO THE UPPER AND LOWER SURFACES THEREOF WHICH BALLS DEFINE A PIVOT AXIS LOCATED CENTRALLY OF THE ARMATURE, SAID BALLS BEING INTIMATELY JOURNALLED RESPECTIVELY IN SAID SOCKETS AND PIVOTALLY MOUNTING SAID ARMATURE ON SAID BRACKET IN STATICALLY AND DYNAMICALLY BALANCED CONDITION WITH THE END PORTIONS THEREOF JUXTAPOSED TO SAID POLES, SAID BALLS AND SOCKETS RETAINING SAID ARMATURE AGAINST SIDE PLAY FOR MOVEMENT ABOUT A FIXED PIVOT AXIS. 